1. Field of the Invention
The present general inventive concept relates to an apparatus and method, and more particularly, to a scanning apparatus and method, to correct skewing distortion in an image.
2. Description of the Related Art
In general, a scanning apparatus is a device that scans a document to produce image data with predetermined resolution. Referring to FIGS. 1A and 1B, a general scanning apparatus 10 includes a stage glass 20 on which a document is placed and a scanning head 30 that scans the document while translating below the stage glass 20 from one end of the stage glass 20 to the other. The scanning head 30 includes a light source module 31 that irradiates the document with light and a photoelectric converting device 33 that detects light reflected by the document and converts the detected light into an image signal.
In the conventional scanning apparatus 10, when the scanning head 31 scans a thick book, a region near a folding line A of the book is positioned above the stage glass 20 by a gap d1 while a page region B of the book contacts the stage glass 20, as illustrated FIG. 1B. Accordingly, a focus distance between the light source module 31 and the photoelectric converting device 33 varies as the scanning head 30 moves from the page region B to the folding line A (I1≠I2). Due to such a focus distance difference occurring when the scanning head 30 moves, there arises a problem in that an image of the region near the folding line A has spatial distortion (or skew) or appears to be darker than the image in the page region B, as illustrated in FIG. 1C.